Microsoft Windows Kernel: Elevation of privilege via race condition
Summary
A race condition (CWE-362, with CWE-415 also listed) in the Windows kernel allows an authorized local attacker to elevate privileges. The attacker needs code execution or a low-privileged account on the affected system first, and must win a timing-dependent race. Successful exploitation could lead to full compromise of confidentiality, integrity and availability on that machine.
Affected
- Windows 10 Version 1607 (builds before 10.0.14393.9688)
- Windows 10 Version 1809 (builds before 10.0.17763.9487)
- Windows 10 Version 21H2 (builds before 10.0.19044.7846)
- Windows 10 Version 22H2 (builds before 10.0.19045.7846)
- Windows 11 Version 23H2 (builds before 10.0.22631.7711)
- Windows 11 Version 24H2 (builds before 10.0.26100.9974)
- Windows 11 Version 25H2 (builds before 10.0.26200.9974)
- Windows 11 Version 26H1 (builds before 10.0.28000.3501)
- Windows 11 Version 26H2 (builds before 10.0.26300.9974)
- Windows Server 2016 incl. Server Core (builds before 10.0.14393.9688)
- Windows Server 2019 incl. Server Core (builds before 10.0.17763.9487)
- Windows Server 2022 (builds before 10.0.20348.5870)
- Windows Server 2025 (builds before 10.0.26100.33822)
Fixed in
- Security updates released on November 10, 2026, per the Microsoft Security Update Guide. Install the cumulative update for your build.
- KB article numbers: Unknown.
Workaround
Unknown. No vendor-documented workaround was found in the sources reviewed.
Exploitation
- CISA SSVC: Exploitation none, automatable no, technical impact total.
- No evidence of exploitation in the wild and no public proof of concept found at the time of research.
- Exploit code maturity is Unproven (E:U).
Our recommendation
- Install the November 2026 security update on all affected Windows 10, 11 and Server systems, prioritising terminal servers, shared workstations and systems where untrusted code could run.
- Verify whether older builds (Windows 10 1607, 1809, 21H2) still receive updates or are on Extended Security Updates.
- Check the MSRC page for mitigations and updates, and escalate if CISA adds the CVE to KEV or a public exploit appears.
- Monitor endpoints for privilege escalation activity.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Elevation of privilege – Windows Kernel
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Windows, Windows ESU (Extended Security Updates)
- Updates (KB)
- KB5131291, KB5131085, KB5131096, KB5131090, KB5131087, KB5132061
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- MSRC Security Update Guide: CVE-2026-105566 msrc.microsoft.com
- CVE.org CVE Record: CVE-2026-105566 www.cve.org
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 09:35.
Original description (NVD)
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Kernel allows an authorized attacker to elevate privileges locally.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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